Successful myoblast transplantation in primates depends on appropriate cell delivery and induction of regeneration in the host muscle

In a double-blind, cross-over study, we examined the effect of inhaled budesonide (800 microgram twice daily via Turbohaler) on lung function and various markers of airway inflammation including airway responsiveness to methacholine (PC20), exhaled nitric oxide (NO), eosinophils in induced sputum, bronchoalveolar lavage (BAL), and airway biopsies from 14 patients with mild asthma needing beta2- agonist therapy only. After inhaled steroids, there was a significant increase in FEV1 and PC20, and reduction in exhaled NO. Eosinophils in induced sputum and airway biopsy sections were also significantly decreased, although BAL eosinophil counts remained unchanged. At baseline, significant correlations were observed between exhaled NO and PC20 methacholine (r = 0.64, p < 0.05), exhaled NO and peak expiratory flow rate (PEFR) variability (r = 0. 65, p < 0.05), sputum eosinophils and FEV1 (r = -0.63, p = 0.05), and sputum eosinophils and log PC20 methacholine (r = -0.67, p < 0. 05). After treatment with inhaled steroids, there was a significant correlation between eosinophils in biopsy sections, and BAL, with log PC20 methacholine. It is likely that these parameters represent different aspects of the inflammatory process, which are all inhibited by inhaled steroids.     

Is bronchial hyperresponsiveness more frequent in women than in men? A population-based study

To test the hypothesis that a greater proportion of women than men react to methacholine challenge and investigate the possible reasons for any differences observed, we recruited 495 subjects 20 to 44 yr of age (50.9% male) in Paris and 304 subjects (51.3% male) in Montpellier (France), as part of the European Community Respiratory Health Survey. The proportion of responders (PD20 < or = 4 mg methacholine) was 33.7% in women and 11.9% in men (odds ratio = 3.8; 95% confidence interval = 2.4-6.0) in Paris and 43.2% in women and 29.5% in men (odds ratio = 1.8; 95% confidence interval = 1.1-2.9) in Montpellier. These differences could not be explained by asthma, respiratory symptoms, atopy, or lung function parameters. In stepwise logistic regressions including sex, asthma, and asthma-like symptoms, nasal allergies, atopy, baseline FEV1, FEV1%pred, FVC, and FEV1%FVC, the odds-ratios for the effect of female sex on PD20 < or = 4 mg methacholine were 5.2 (3.0-9.0) in Paris and 2.2 (1.2-3.8) in Montpellier. Reacting to low doses of methacholine (PD20 < or = 0.5 mg) was associated with asthma and atopy in both men and women. In contrast, reacting to doses between 0.5 and 4 mg was associated with asthma and atopy only in men and with heavy tobacco consumption only in women. We conclude that the excess of hyperresponsiveness in women is not due to their having smaller lung size or airway caliber than men and may be related to a greater susceptibility to smoking.     

Relationship between lung inflammation, changes in lung function and severity of exposure in victims of the Bhopal tragedy

The world's worst chemical industrial disaster, which occurred at Bhopal on 2-3 December, 1984, resulted in considerable respiratory morbidity in the exposed population. Therefore, a study was planned to evaluate the relationship between lower respiratory tract inflammation, lung function and severity of exposure. Sixty patients exposed to methyl isocyanate and presenting with respiratory symptoms were studied using bronchoalveolar lavage (BAL) 1-7 yrs after the accident. Pulmonary function tests included forced vital capacity (FVC) and forced expiratory volume in one second (FEV1). An index of severity of exposure was derived retrospectively on the basis of the acute symptoms in the victims themselves or the occurrence of death among their family members. Total lung inflammatory cells (p < 0.01) and absolute numbers of macrophages (p = 0.01) and lymphocytes (p < 0.05) increased as severity of exposure increased. FEV1/FVC % (p = 0.05) was also significantly lower as severity of exposure increased. Moderately exposed subjects had significantly lower FEV1/FVC % (p < 0.05) compared to those mildly exposed. In nonsmokers, BAL neutrophils, both percentage and absolute numbers, showed significant negative correlations with FEV1 % predicted (rs = -0.350, p < 0.05; and rs = -0.374, p < 0.01, respectively). Neutrophil percentage was negatively correlated with FEV1/FVC % (rs = -0.378; p < 0.01). Absolute lymphocytes had significant negative correlations with FVC % pred (rs = -0.318; p < 0.05). Macrophages had significant positive correlations with FVC % pred (rs = 0.322; p < 0.05) and FEV1 % pred (rs = 0.433; p < 0.01). Radiographic abnormalities (International Labour Organization (ILO) classification) were associated with decline in FEV1 % pred (p < 0.05). This study suggests that pulmonary function abnormalities occur in gas-exposed subjects as a consequence of an abnormal accumulation of lung inflammatory cells (lymphocytes and neutrophils), and that the intensity of lung inflammation and reduction in pulmonary function are greater in severely exposed subjects. As it has been observed that decline in pulmonary function is associated with radiographic abnormalities, there is a suggestion that injury following toxic gas exposure can lead to irreversible lung damage.     

Pentoxifylline versus placebo in the treatment of infertility associated with minimal or mild endometriosis: a pilot randomized clinical trial

The long-term outcome of pulmonary function was evaluated in farmer's lung (FL) patients compared to representative control farmers. This is, to our knowledge, the first such study which has included a control group. Clinical examinations were conducted in 89 FL patients and 84 control farmers, matched by age, sex, and smoking habits. The mean time after the first diagnosed episode of FL was 14 yrs. The mean transfer factor of the lung for carbon monoxide (TL,CO) was on average 12% lower (p < 0.001) in FL patients compared to control farmers. In spirometry, the mean maximum expiratory flow at 50% of vital capacity (MEF50) was lower (p = 0.08) in FL patients but there were no differences in mean vital capacity (VC) or forced expiratory volume in one second (FEV1) between FL patients and control farmers. However, airway obstruction, defined as an FEV1/VC less than 88% of predicted, was more common in FL patients than in control farmers (33 versus 17%; p = 0.02). Patients who had had recurrent episodes of FL had a significantly lower mean TL,CO compared to those FL patients who had experienced only a single episode. In conclusion, impairment of the pulmonary transfer factor is the most important long-term consequence of farmer's lung. However, farmer's lung may also lead to development of airway obstruction.     

Ventilation and gas exchange in patients with chronic renal failure treated with hemodialysis (HD) and intermittent peritoneal dialysis (IPD)

In 18 patients with chronic renal failure treated by hemodialysis (HD) before, during and after dialysis procedure breathing patterns and blood gases were estimated. Significant changes in PdCO2 and PvCO2 during HD may confirm hypothesis that CO2 diffusion into the dialysis fluid play a role in hypoventilation and hypoxemia during HD. PaO2 decrease in patients treated by peritoneal dialysis (PD) after infusion 21 of fluid into the peritoneal cavity. Increase in minute ventilation (VE) and oxygen consumption (ViO2) at 2nd and 4rs hour of PD indicate that substrate metabolism during dialysis relates to alternations in ventilation. In all patients before dialysis treatment presence of ventilation disturbances of restrictive typ were demonstrated with decreased vital capacity (VC), reduced maximal ventilation (MBC) and lower one-second forced expiratory volume (FEV1). Residual volume (RV) was significantly higher. After HD we observed a significant increase of total lung capacity (TLC) and decrease of RV, whereas after PD a significant decrease of RV.     

CTLA4Ig inhibits airway eosinophilia and hyperresponsiveness by regulating the development of Th1/Th2 subsets in a murine model of asthma

Complete T-cell activation requires two distinct signals, one delivered via the T-cell receptor, and the second "co-stimulatory" signal through CD28/B7 ligation. Previous studies showed that the blockade of CD28/B7 ligation alters differentiation of Th1/Th2 lymphocyte subsets in vitro and in vivo. The present study was designed to determine the effect of a CD28/B7 antagonist (CTLA4Ig) on Th1/Th2 development in Schistosoma mansoni-sensitized and airway-challenged mice. Treatment of mice with CTLA4Ig beginning 1 wk after sensitization abolished airway responsiveness to intravenous methacholine determined 96 h following antigen challenge. We also found a significant reduction in bronchoalveolar lavage (BAL) eosinophilia, and reduced peribronchial eosinophilic infiltration and mucoid-cell hyperplasia. Furthermore, CTLA4Ig treatment significantly decreased interleukin (IL)-4 and IL-5 content in BAL fluid in vivo, and the production of IL-5 by lung lymphocytes stimulated with soluble egg antigen (SEA) in vitro. In contrast, the content of interferon-gamma in BAL fluid and supernatant from SEA-stimulated lung lymphocytes from CTLA4Ig-treated mice was increased significantly compared with untreated animals. Thus, CTLA4Ig inhibits eosinophilic airway inflammation and airway hyperresponsiveness in S. mansoni-sensitized and airway-challenged mice, most likely due to attenuated secretion of Th2-type cytokines and increased secretion of Th1-type cytokines.     

The effect of salmeterol on nocturnal symptoms, airway function, and inflammation in asthma

STUDY OBJECTIVE: To determine the efficacy of salmeterol alone in a group of patients with moderate asthma with nocturnal worsening of symptoms. DESIGN: Double-blind, randomized, placebo-controlled crossover study. SETTING: Tertiary care hospital specializing in respiratory diseases. PARTICIPANTS: Ten patients with nocturnal asthma. INTERVENTIONS: Subjects were randomized to salmeterol, 100 micrograms twice daily, or placebo for 6 weeks with a 1-week washout between treatment periods. Symptoms, nocturnal awakenings, and beta 2-agonist use were recorded daily. Spirometry was performed at weeks 1 and 6 of each period at bedtime and at 4 AM, and methacholine challenge was performed at 4 AM followed by bronchoscopy with BAL. BAL fluid analysis included cell count and differential count, eosinophil cationic protein, Charcot-Leyden crystal protein, leukotriene B4, and thromboxane B2. RESULTS: The percentage of nights with awakenings decreased significantly with salmeterol (69.8 +/- 8.7% vs 30.6 +/- 10.8% for placebo and salmeterol, respectively; p = 0.02). The percentage of 24-h days with supplemental inhaled beta 2-agonist use significantly decreased with salmeterol (85.9 +/- 9.4% vs 70.4 +/- 10.1% for placebo and salmeterol, respectively; p = 0.04). There were no significant differences in bronchial reactivity, 4 AM FEV1, overnight percentage change in FEV1, or indexes of airway inflammation. CONCLUSIONS: Salmeterol alone improves the number of nocturnal awakenings and supplemental 24-h beta 2-agonist use in nocturnal asthma without significantly altering lung function and airway inflammation.     

Bronchial hyperresponsiveness and toluene diisocyanate. Long-term change in sensitized asthmatic subjects

Long-term change in nonspecific and specific bronchial hyperresponsiveness was studied in 16 subjects with asthma induced by toluene diisocyanate (TDI). A significant positive correlation between months of follow-up and provocative dose inducing a 20 percent fall in FEV1 (PD20FEV1) methacholine was observed in 5 of 16 subjects. In 4 of these 5 subjects, a PD20FEV1 > 1 mg of methacholine was observed 30 to 48 months after the end of TDI exposure. In most subjects, nonspecific bronchial hyperresponsiveness did not change. Nine of 16 subjects became nonresponsive to TDI at follow-up examination, but only 3 of these showed a significant increase in PD20FEV1 methacholine. Seven subjects were still responsive to TDI. Recovery from TDI-induced asthma can occur and only after long-term work cessation. Nonspecific bronchial hyperresponsiveness to methacholine can persist even in the absence of bronchial hyperresponsiveness to TDI, suggesting permanent chronic damage to mechanisms controlling airway tone.     

The content of asbestos bodies in the bronchoalveolar fluid as a parameter of an increased pulmonary asbestos load

Pulmonary asbestos burdens are usually determined by quantitative pulmonary dust analysis. The aim of this study was to investigate the value of bronchoalveolar lavage (BAL) for this purpose. First, the upper limit of normal for asbestos bodies (AB) in BAL fluid was established using a reference group of 371 patients with no evidence of increased exposure to asbestos. 99% of these patients had less than 0.5 AB/ml. In order to see whether BAL fluid AB concentration reflected pulmonary tissue content, BAL fluid and lung tissue from a further 64 patients with diverse histories of asbestos exposure were investigated. There was a positive association between AB concentration in BAL fluid and lung tissue only for the overall group of 64 patients (r = 0.86; P < 0.001). Twelve of 13 patients with more than 1 AB/ml and ten patients with more than 5 AB/ml had more than 1000 AB/cm3 lung tissue, a value that is usually exceeded in asbestosis. When the upper concentration limit was set at 0.5 AB/ml for BAL fluid and 50 AB/cm3 for lung tissue, only two out of 64 patients had a false positive value (specificity 95%), but eleven patients had false negative results (sensitivity 58%). These investigations establish that concentrations of > or = 0.5 AB/ml are a reliable indicator of increased asbestos exposure and concentrations > 1 AB/ml are associated with a higher probability of having more than 1000 AB/cm3 lung tissue. However, exclusion of increased asbestos exposure is not possible on the basis of negative BAL findings, since the sensitivity of the method is too low.     

Guidelines for reporting results of quality of life assessments in clinical trials

BACKGROUND: Current guidelines on the management of asthma advocate the use of anti-inflammatory treatment in all but mild disease. They define disease control in terms of clinical criteria such as lung function and symptoms. However, the relationship between the clinical control of the disease and inflammation of the airways is not clear. A cross sectional study was therefore undertaken to investigate the relationship between airways inflammation and measures of clinical control and bronchial hyperresponsiveness in asthmatic patients treated with inhaled steroids. METHODS: Twenty six atopic adults (19-45 years) with mild to moderate asthma (baseline forced expiratory volume in one second (FEV1) > or = 50% predicted, concentration of histamine causing a 20% fall in FEV1 (PC20) 0.02-7.6 mg/ml) on regular treatment with inhaled steroids entered the study. Diary card recordings during the two weeks before a methacholine challenge test and bronchoscopic examination were used to determine peak flow variability, symptom scores, and use of beta 2 agonists. Biopsy specimens were taken by fibreoptic bronchoscopy from the carina of the right lower and middle lobes, and from the main carina. Immunohistochemical staining was performed on cryostat sections with monoclonal antibodies against: eosinophil cationic protein (EG1, EG2), mast cell tryptase (AA1), CD45, CD22, CD3, CD4, CD8, CD25, and CD45RO. The number of positively stained cells in the lamina propria was counted twice by using an interactive display system. RESULTS: There were no differences in cell numbers between the three sites from which biopsy specimens were taken. The PC20 for methacholine was inversely related to the average number of total leucocytes, EG1+, and EG2+ cells, mast cells, CD8+, and CD45RO+ cells in the lamina propria. These relationships were similar for each of the biopsy sites. Symptom scores, beta 2 agonist usage, FEV1, and peak flow variability were not related to any of the cell counts. CONCLUSIONS: Infiltration of inflammatory cells in the lamina propria of the airways seems to persist in asthmatic outpatients despite regular treatment with inhaled steroids. The number of infiltrating leucocytes such as mast cells, (activated) eosinophils, CD8+, and CD45RO+ cells in bronchial biopsy specimens from these patients appears to be reflected by airway hyperresponsiveness to methacholine, but not by symptoms or lung function. These findings may have implications for the adjustment of anti-inflammatory treatment of patients with asthma.     

Metered-dose inhaler to deliver methacholine in bronchial provocation testing: a pilot study

BACKGROUND: Nonspecific bronchial provocation tests may be simplified by the use of hand-held devices to deliver methacholine. OBJECTIVE: To study the feasibility of using a metered-dose inhaler (MDI) to administer methacholine in bronchial provocation tests, and the ability of such a device to diagnose bronchial hyperresponsiveness (BHR) accurately. METHODS: In an open randomized crossover pilot study, we compared the provocative dose that induces a 20% fall in FEV1 (PD20 FEV1) obtained with the methacholine MDI with that obtained using a conventional nebulizer in 20 hyperresponsive and 20 nonhyperresponsive subjects. The MDI delivers 400 doses of 100 microg of methacholine, and was used via a spacer. Bronchial hyperresponsiveness (BHR) was defined as a PD20 FEV1 <2,000 microg with the conventional test using the nebulizer. The tests were performed in each subject in a randomized order, 1 to 7 days apart. RESULTS: Of the subjects who had a nebulizer PD20 FEV1 <2,000 microg, all but one had an MDI PD20 FEV1 <800 microg. When 800 microg was taken as the threshold for the diagnosis of BHR with the MDI test, the accuracy of this test to diagnose BHR was 97.5%, and the two tests were highly concordant for the diagnosis of BHR (Pearson chi2, 36.19; p<0.0001). CONCLUSION: A hand-held device may be suitable for delivery of methacholine during bronchial provocation tests, if these results are confirmed in large samples.     

Inhaled steroids modify bronchial responses to hyperosmolar saline

We investigated the effects of inhaled beclomethasone dipropionate (BDP) on airway sensitivity (provocative dose producing a 20% fall in forced expiratory volume in one second (FEV1) from baseline (PD20)) and reactivity (slope of the dose-response curve) to inhaled aerosols of hyperosmolar (4.5%) saline, and histamine or methacholine. This was an open study on 13 patients referred to the laboratory by their respiratory physician for investigation of their asthma. These challenges were performed on separate days before (initial visit) and 8.8 +/- 0.8 (SD) weeks (range 5.6-12.4 weeks) after (visit 1) a treatment period with BDP (dose range 600-1,500 micrograms.day-1). At visit 1 there was a significant reduction in sensitivity to 4.5% NaCl and histamine/methacholine and in reactivity. The PD20 increased 5.6 fold for 4.5% NaCl and 4.1 fold for histamine/methacholine. All patients remained responsive to histamine/methacholine and a fall in FEV1 > 20% to 4.5% saline was documented in 10 of the 13 patients. We conclude that treatment with BDP reduces sensitivity and reactivity to both osmotic and pharmacological challenge.     

Comparison of bronchial reactivity to ultrasonically nebulized distilled water, exercise and methacholine challenge test in asthmatic children

We studied the responses to ultrasonically nebulized distilled water (UNDW) challenge, exercise challenge and methacholine challenge in asthmatic children. Fifty-four asthmatic and fourteen nonasthmatic control children participated in this study. The UNDW inhalation test was by the methodology described by Anderson. The average output of water was approximately 3.0 mL/min (SD = .1) and inhalation times were 30 seconds, one minute, two minutes and four minutes. Some subjects performed exercise challenge on a bicycle ergometer and methacholine challenge by an Astrograph technique. Twenty-three of 54 asthmatic patients (42.6%) and none of the controls showed a fall in FEV1 greater than 20% with UNDW challenge. The fall in FEV1 with UNDW correlated with that induced by exercise challenge (r = .89) and Log Dmin, which may reflect bronchial sensitivity (r = .70). Our method is not sensitive enough for detecting bronchial hyperresponsiveness in all asthmatic children. Bronchoconstriction induced by UNDW has a similar mechanism of action as exercise and methacholine.     

Distribution of asbestos bodies in the human lung as determined by bronchoalveolar lavage

Asbestos-related lung diseases tend to have distinct local distributions, for example, asbestosis first appears and tends to be more severe in the peripheral parts of the lower lung zones. The risk for asbestosis is related to the total asbestos burden of the lung. This suggests that the lower lobes in asbestos-exposed individuals may contain more asbestos than the other lobes. To test whether such topographic differences exist, we compared the number of retrieved asbestos bodies (AB) per ml BAL fluid in three groups of occupationally asbestos-exposed subjects who underwent BAL at different sampling sites. In Group 1 (n = 24) we performed BAL at three sites, namely in a segment of the right upper, right middle, and right lower lobe, to evaluate differences in asbestos body burden from lung apex to basis. There was a distinct increase in BAL asbestos body concentrations from the upper (21.2 +/- 9.1 AB/ml BAL fluid) to the middle (30.4 +/- 12.8 AB/ml BAL fluid) and to the lower lobe (56.0 +/- 20.2 AB/ml BAL fluid), all differences being significant (p < 0.01). In Group 2 (n = 40), we found good interlobar correlations for asbestos body counts between the right middle lobe (21.0 +/- 5.8 AB/ml BAL fluid) and the lingula (22.4 +/- 5.9 AB/ml BAL fluid) (r = 0.941, p < 0.001) and, in Group 3 (n = 15), between the ventral basal segment of the right (41.2 +/- 13.6 AB/ml BAL fluid) and left lung (39.0 +/- 13.6 AB/ml BAL fluid) (r = 0.966, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Long-term exposure to retinoic acid induces the expression of IRK1 channels in HERG channel-endowed neuroblastoma cells

T-cell types are important in maintaining immune homeostasis in the lung and their imbalance may be associated with several diseases. We examined the relationship between bronchoalveolar lavage (BAL) T-cell subset profiles and the clinical course of 46 patients with idiopathic pulmonary fibrosis (IPF). A flow cytometry cell sorter (FACS) was used to analyse the T-cell subsets. Pulmonary function tests (PFT) were performed at baseline and 6-12 months later. Patients were divided into two groups according to their CD4/CD8 ratio: CD4/CD8 >1 (group 1, n=21); and CD4/CD8 <1 (group 2, n=25). A lower percentage of lymphocytes, a higher percentage of CD8/S6F1 cells (cytotoxic T-lymphocytes) and a higher percentage of neutrophils were found in the BAL in group 2 compared to group 1 (11+/-7.5% versus 19+/-13.2%; p=0.024 and 29.8+/-17.6% versus 13.3+/-6.9%; p=0.068, respectively for lymphocytes and cytotoxic T-lymphocytes; and 8+/-11% versus 29+/-27%; p=0.003 for neutrophils). Inversely, in the peripheral blood, the distribution of CD8/S6F1 cells was lower in group 1 than in group 2 (8.3+/-6.9% versus 33.4+/-16.5%; p=0.0048). The patients were followed over a period of 1 yr in order to test whether those findings could determine efficacy of therapy. The baseline transfer factor of the lung for carbon monoxide (TL,CO) capacity in group 1 and group 2 was 59+/-22% and 51+/-21%, respectively (p=0.29), but only in group 1 was the TL,CO capacity improved significantly in response to steroids treatment after 6-12 months. IPF patients with a higher percentage of lymphocytes, a lower percentage of neutrophils, CD4/CD8 >1 and a low percentage of CD8/S6F1 may have a more benign course of disease. These parameters may identify an early stage of reversible disease responsive to therapy. We conclude that these measurements may be a useful tool in monitoring response to treatment in patients with idiopathic pulmonary fibrosis.     

Increased LTB4 metabolites and PGD2 in BAL fluid after methacholine challenge in asthmatic subjects

The bronchoconstrictor potency of inhaled methacholine is widely used to assess airway responsiveness. However, evidence has accumulated that methacholine inhalation challenge may lead to an inflammatory response in the lower respiratory tract. We therefore compared cellular, leukotriene and prostanoid profiles in bronchoalveolar lavages (BAL) obtained five hours after methacholine challenge to control lavages without prior challenge. Eight subjects with asymptomatic to mild bronchial asthma and nine nonatopic healthy controls were enrolled in the study. Without prior challenge, the percentage of BAL eosinophils was higher in the asthmatic subjects ((mean +/- SD), 1.1 +/- 0.9%) than in the control subjects (0.1 +/- 0.1%. Leukotriene B4 (LTB4), and its omega-oxidation products (20-OH-LTB4 and 20-COOH-LTB4) were the only leukotrienes detectable in the baseline BAL fluids in five of the eight asthmatic patients. After methacholine challenge, no change in BAL cell profile occurred, but in the asthmatic patients, the total amounts of LTB4 and its omega-oxidation products rose from 0.52 +/- 0.50 ng.ml-1 (pre-challenge) to 1.55 +/- 1.32 ng.ml-1 (post-challenge), and prostaglandin D2 (PGD2) rose from 49.1 +/- 15.7 (pre-challenge) to 94.4 +/- 25.4 pg.ml-1 (post-challenge), with no change in 6-keto-PGF1 alpha, thromboxane B2 (TXB2), and prostaglandins F2 alpha and E2 (PGF2 alpha and PGE2). In the healthy controls, no consistent change in BAL cell profile and mediators occurred after methacholine provocation. We conclude that inhaled methacholine stimulates LTB4 and PGD2 release in asthmatics, but not in healthy controls, without affecting the number of inflammatory cells in BAL fluid.     

Grain dust-induced airflow obstruction and inflammation of the lower respiratory tract

To investigate the relationship between the physiologic and biologic effects of grain dust inhalation, we exposed 15 nonsmoking, nonasthmatic, nonatopic male grain handlers to buffered saline and aqueous corn dust extract by inhalation challenge in a crossover study. The inhalation challenges to buffered saline and corn dust extract were separated by at least 14 d. Compared with buffered saline, inhalation of corn dust extract resulted in significant airflow obstruction, which was observed within 30 min of exposure and persisted for 5 h. Inhalation of corn dust extract resulted in an acute inflammatory response characterized by higher concentrations of neutrophils (p = 0.001), IL-1 beta (p = 0.001), IL-1RA (p = 0.001), IL-6 (p = 0.001), IL-8 (p = 0.001), and TNF-alpha (p = 0.04) in bronchoalveolar lavage (BAL) fluid. mRNA levels specific for IL-1 beta, IL-1RA, IL-6, and IL-8 from cells present in the BAL fluid were significantly greater after challenge with corn dust extract than after challenge with buffered saline. Importantly, no significant differences were observed in the concentration of lymphocytes or eosinophils in the BAL fluid following inhalation of corn dust extract, and the concentrations of histamine and 15-HETE were similar in BAL fluid after the two challenges. The maximal percentage decrease in FEV1 was significantly associated with the absolute neutrophil concentration in the BAL fluid (p = 0.001), as well as the concentration of TNF-alpha (p = 0.03), IL-1 beta (p = 0.005), IL-1RA (p = 0.001), IL-6 (p = 0.001), and IL-8 (p = 0.001) in the BAL fluid.(ABSTRACT TRUNCATED AT 250 WORDS)     

Local expansion of allergen-specific CD30+Th2-type gamma delta T cells in bronchial asthma

BACKGROUND: T lymphocytes infiltrating airways during the allergic immune response play a fundamental role in recruiting other specialized cells, such as eosinophils, by secreting interleukin 5 (IL-5), and promoting local and systemic IgE synthesis by producing IL-4. Whether these presumed allergen-specific T cells are of mucosal or systemic origin is still a matter of conjecture. MATERIALS AND METHODS: Immunophenotype, IL-4 production, and in vitro proliferative response to specific or unrelated allergens were analyzed in the bronchoalveolar lavage (BAL) fluid lymphocyte suspensions obtained from untreated patients with allergic asthma. Healthy subjects and patients affected by pulmonary sarcoidosis, a granulomatous lung disease characterized by infiltrating Th1 CD4+ lymphocytes, served as controls. RESULTS: The proportions of gamma delta T lymphocytes, mostly CD4+ or CD4- (-)CD8-, was higher in asthmatic subjects than in controls (p < 0.05). Most BAL gamma delta CD4+ lymphocytes of asthmatic patients displayed the T cell receptor (TCR)-gamma delta V delta 1 chain. While CD30 antigen coexpression on the surface of BAL alpha beta(+) T lymphocytes was low (ranging from 5 to 12%), about half of pulmonary gamma delta T cells coexpressed it. These cells produced IL-4 and negligible amounts of interferon-gamma (IFN gamma), and proliferated in vitro in response to purified specific but not unrelated allergens. In contrast, control or sarcoidosis gamma delta T cells never displayed the CD30 surface molecule or produced significant quantities of IL-4. CONCLUSIONS: These findings not only confirm our previous hypothesis that the allergen-specific Th2-type lymphocytes found in the lungs of asthmatic patients are gamma delta T cells belonging to airway mucosal immunocytes, but also strongly support the notion that asthma is a local rather than a systemic disease.     

Micronodules and emphysema in coal mine dust or silica exposure: relation with lung function

The aim of this study was to investigate the respective effects of micronodules and pulmonary emphysema, detected by computed tomography (CT), on lung function in workers exposed to silica and coal mine dust. Eighty-three subjects exposed to silica (n=35) or to coal mine dust (n=48), without progressive massive fibrosis, were investigated by high-resolution and conventional CT scans to detect micronodules and to quantify pulmonary emphysema by measuring the relative area of the lung with attenuation values lower than -950 Hounsfield units. Sixty-six (54.5%) subjects had evidence of micronodules on CT scans. Smokers had micronodules more rarely than nonsmokers. Significant correlations were found between the forced expiratory volume in one second (FEV(1); % predicted) (r=-0.41, p<0.001), FEV1/vital capacity (VC) (r=-0.61, p<0.001), diffusing capacity of the lung for carbon monoxide (DL,CO) (r=-0.36, p<0.001) and the extent of emphysema. No difference was demonstrated in the linear relationships between the extent of emphysema and the pulmonary function according to the type of exposure or the presence of micronodules on CT scans. This study suggests that micronodules detected by computed tomography have no influence, by themselves, on pulmonary function and that they should only be considered as a marker of exposure.